The replacement of missing and hopeless teeth with dental implants is a very common practice. Once an implant is surgically placed, it is usually allowed to heal for a time frame of a few weeks in order for the process of its osseointegration with the jaw to be completed, before it can receive its final prosthesis. A part known as a healing abutment is coupled with the implant immediately after the latter is placed in the jaw, or at a later stage after the osseointegration process has been completed, in order to protect the prosthetic connection of the implant from the invasion of soft and/or hard tissue. This ensures the accessibility of the prosthetic connection of the implant after osseointegration is complete and it is desired to carry out the process of the prosthetic rehabilitation of the implant. Thus, after the completion of osseointegration, a process that may take from one to nine months, the healing abutment is disconnected from the implant and an impression post replaces it in order to proceed with the impression stage of the implant. Following the impression stage, the healing abutment is reconnected with the implant and finally it is replaced by the final dental implant prosthesis, which is supported by the implant that is anchored in the jaw. The existing healing abutments and impression posts on the market, along with the methodology involved in their use in the different stages of implant treatment, present a lot of shortcomings. Furthermore, the existing healing abutments and impression posts provided to the dentist by the different implant supply companies are prefabricated and it would be a great advantage if the dentist was be able to fabricate their own custom abutments and impression posts with improved characteristics using the molds of our invention.
Thus, before the invention described herein, dentists faced a significant problem arising from the limitations in choice of shape, size and material of fabrication of the healing abutments and impression posts that are provided by the different implant companies.
It is a common practice among dentists to use dental implants and parts from more than one implant company, which often have available healing abutments and impression posts of different dimensions and shapes. The mismatch between the parts supplied by the different implant companies forces the dentists to change their utilized protocols of treatment between different clinical cases, depending on the company that supplied the utilized implant.
The healing abutments available on the market with their relatively narrow cylindrical shape generate a narrow gingival emergence profile and this creates difficulties at the stage of the final implant prosthesis installment onto the implant, due to the difference in shape and dimensions between the gingival emergence profile and the emergence profile of the final prosthesis. The consequence of the above is that during prosthesis installment the latter pinches and traumatizes the soft tissue causing bleeding in the area and pain to the patient making necessary the use of local anesthesia.
The healing abutments available from most of the implant supply companies are made out of titanium and modifications to them are not recommended, even when modification is necessary. Thus, the use of large size healing abutments in many clinical cases is impossible because their body will interfere with the adjacent teeth making their installation onto the implant without any modifications of their size and shape difficult to impossible.
Before this invention, in order for a dentist to overcome the problem of a narrow gingival emergence profile developed from the healing abutments available in the market, it was necessary on the dentist's behalf to use a time and money consuming process for both the dentist and the patient. Specifically, the dentist utilizes sequentially new temporary prostheses expanding laterally the volume of the sub-gingival portion of the temporary prostheses gradually, in order to expand the gingival emergence profile. This is a process that can take anywhere between a few weeks to a few months until it is successfully completed.
In a small scale today there are healing abutments that can be scanned by a digital scanner in order for a digital impression to be fabricated. The disadvantage of these healing abutments is that they are not customizable and thus they fail to generate a three dimensionally ideal shape gingival emergence profile in all clinical cases. This does not allow the dentist to take full advantage of the tools that digital dentistry through CAD-Cam machinery potentially provides to the dentist.
Another important clinical problem is the accurate recording and transfer of the gingival emergence profile at the impression stage, from the mouth to the working cast, where the lab technician will fabricate the final implant prosthesis. The impression posts available from the different implant companies have a narrow emergence profile that corresponds to the narrow emergence profile of the healing abutments they provide and do not have properties that allow their ready customization. A dentist that has created a custom emergence profile through the use of a temporary prosthesis finds a difficult situation as to the way that they can record and transfer accurately the created custom gingival emergence profile from the mouth to the working cast, due to the difference in shape and dimensions of the latter as compared to the shape and the dimensions of the impression posts available to the dentist from the implant supply companies.
The impression posts that are commercially available are straight. Angulated impression posts are not available in the market. Thus, in clinical cases where the implant is located in the jaw with angulations different than the ones of the adjacent teeth, the dentist might not be able to install onto the implant a straight impression post as its body may interfere with the crowns of the adjacent teeth or the impression posts of the adjacent implants. Moreover, at the stage of impression removal from the mouth the different angulations of the aforementioned elements might lead to the development of areas of deformation of the impression material around the impression post, a fact that negatively affects the precision of the impression.
The impression posts available today also do not have the design and properties that allow their ready modification to temporary abutments that can be used to support a temporary prosthesis.
There is a patent application (US 20140124969) that concerns a jig that is utilized for the fabrication of straight asymmetrical custom healing abutments. That patent application concerns a jig that the application says can fabricate straight, custom, asymmetrical healing abutments with irregular surfaces. There is no claim for the utilization of this jig for the fabrication of, in addition to the straight healing abutments, angulated healing abutments and straight or angulated impression posts.
U.S. Pat. No. 8,628,327B1 describes the use of a mold with wells and abutments. However, wells and abutments in that patent have at least one asymmetrical cross-section and irregular surfaces to accommodate the introduction of additional biomaterial in order to apply that patent's method of addressing the void where a tooth is or was extracted. This asymmetrical cross-section surface limits the abutment to fitting in only one functional position on the implant as opposed to the use of a symmetrical cross-section that permits the positioning in many different orientations. In addition, a patient's soft tissue will not adapt as well to the irregular surfaces as it would to a regular surface. The use of the additional biomaterial by U.S. Pat. No. 8,628,327B1 that is added to the well to make the abutment, and which expands in close relationship to its prosthetic platform, also detracts from the usefulness of this patent's method because it does not generate and establish a better zone of connective tissue attachment and adhesion and provide for the presence of a micro-gap between the different materials in this sensitive biologically area as does a regular surface and a material such as polished titanium.
U.S. Pat. No. 8,628,327B1 also does not describe that its wells can be used to make impression posts that can be customized to correspond to a gingival emergence profile. In addition, if the wells of this patent were used to try to make an impression post, the impression post will not match the abutment because the patent teaches the use of the additional biomaterial to the abutment and thus the impression post made from the well will be different and the impression post cannot act as an exact replica that records and transfers the information into a working cast. U.S. Pat. No. 8,628,327B1 also does not describe a mold with wells that have two portions (upper and bottom) that can be used to make two-piece abutments and impression posts where their customized parts (a custom abutment cap and a custom impression abutment cap) are interchangeable on the abutment core. Thus, the patent does not teach that these parts can be interchangeably snapped onto the abutment core that is coupled to the implant, a feature that avoids the repetitive coupling and uncoupling that can induce harmful hard and soft tissue recession.
U.S. Pat. No. 8,628,327B1 also does not describe that its wells can be modified by the introduction of a curable elastomeric material to replicate the sub gingival portion of a dentist-modified abutment or implant prosthesis in order to accommodate the exact replication of this portion into an impression post.
U.S. Pat. No. 8,628,327B1 also does not teach a mold with wells that make abutments and impression posts that can be oriented in different angulations towards the vertical plane by angulation of the sockets comprising prosthetic connections of the abutments and impression posts. Instead, U.S. Pat. No. 8,628,327B1 suggests that the wells themselves should be aligned in different angulations toward the implant analogs located at the mold's base. Such a use of wells cannot achieve the advantages of applicant's invention for fit and precision of the resulting abutments and impression posts.